US5002701A - Light polarizing materials and suspensions thereof - Google Patents

Light polarizing materials and suspensions thereof Download PDF

Info

Publication number
US5002701A
US5002701A US07/428,103 US42810389A US5002701A US 5002701 A US5002701 A US 5002701A US 42810389 A US42810389 A US 42810389A US 5002701 A US5002701 A US 5002701A
Authority
US
United States
Prior art keywords
light
polarizing
pyrazine
compound
particles
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US07/428,103
Other languages
English (en)
Inventor
Robert L. Saxe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Research Frontiers Inc
Original Assignee
Research Frontiers Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US07/309,693 external-priority patent/US4877313A/en
Priority to CA000602176A priority Critical patent/CA1336858C/en
Priority claimed from CA000602176A external-priority patent/CA1336858C/en
Assigned to RESEARCH FRONTIERS INCORPORATED reassignment RESEARCH FRONTIERS INCORPORATED ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: SAXE, ROBERT L.
Priority to US07/428,103 priority patent/US5002701A/en
Application filed by Research Frontiers Inc filed Critical Research Frontiers Inc
Assigned to RESEARCH FRONTIERS INCORPORATED, A CORP. OF DE reassignment RESEARCH FRONTIERS INCORPORATED, A CORP. OF DE MERGER (SEE DOCUMENT FOR DETAILS). 9-19-89 - DE Assignors: RESEARCH FRONTIERS INCORPORATED, A NY CORP.
Priority to CA002027349A priority patent/CA2027349C/en
Priority to EP90402918A priority patent/EP0425344B1/de
Priority to DE69008999T priority patent/DE69008999T2/de
Priority to KR1019900016868A priority patent/KR0168652B1/ko
Priority to JP2288254A priority patent/JP2871837B2/ja
Priority to US07/608,534 priority patent/US5130057A/en
Publication of US5002701A publication Critical patent/US5002701A/en
Application granted granted Critical
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/08—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of polarising materials
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
    • G02B5/3033—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/17—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on variable-absorption elements not provided for in groups G02F1/015 - G02F1/169
    • G02F1/172—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on variable-absorption elements not provided for in groups G02F1/015 - G02F1/169 based on a suspension of orientable dipolar particles, e.g. suspended particles displays

Definitions

  • This invention relates to light-polarizing materials, to set suspensions and fluid suspensions thereof, and to light valves containing such fluid suspensions.
  • Light-polarizing materials such as colloidal suspensions of herapathite and herapathite-like light-polarizing crystals, are described in U.S. Pat. Nos. 1,951,664 (Land) and 2,178,996 (Land), respectively.
  • U.S. Pat. No. 2,237,567 (Land) discloses the production of light-polarizing material in sheet form by various methods including application of a solution of iodine and an iodide to a sheet of polyvinyl alcohol which had been previously stretched to orient the molecules therein.
  • Numerous other patents relating to light-polarizing materials, set suspensions thereof and laminated products derived therefrom and uses thereof are in the art including, for example, U.S. Pat. Nos.
  • sheet polarizers important uses for laminated set suspensions of light-polarizing materials, often referred to as "sheet polarizers", include lenses for polarized sunglasses, components of the twisted nematic and other types of liquid crystal displays and filters of various types including contrast enhancement filters for use in conjunction with light emissive displays.
  • the sheet polarizers thus employed are well known to be frequently subject to degradation due to high levels of heat, ultraviolet radiation and/or especially moisture.
  • Fluid suspensions of light-polarizing and other materials have been used in light valves, comprising a cell containing a fluid suspension of minute particles which can be oriented by an electric or magnetic field to change the transmission of light through the suspension. See for example, U.S. Pat. Nos. 3,708,219 (Forlini et al), 3,743,382 (Rosenberg), 4,078,856 (Thompson et al), 4,113,362 (Saxe et al), 4,164,365 (Saxe), 4,407,565 (Saxe), and 4,422,963 (Thompson et al).
  • U.S. Pat. No. 4,131,334 (Witte et al) describes a process for forming light-polarizing particles by hydrogenation of a nitrogen-containing organic compound, which is then reacted with an appropriate acid to form a salt. The salt may then be reacted, usually with iodine and an inorganic iodide, to produce stable polyiodide particles.
  • An object of the present invention is to provide light-polarizing materials that have high stability with respect to ultraviolet radiation, elevated temperatures and/or high levels of moisture.
  • polyiodides have been known for quite some time.
  • a polyiodide is a complex of iodine atoms and an inorganic or organic matrix. Godina et al discuss polyiodides and other polyhalides in detail in J. Gen. Chem. USSR, 20, (1950), pages 1005-1016.
  • the known polyiodides is the light-polarizing crystalline material, herapathite, which is formed by reaction of quinine bisulfate, iodine and HI. Salts of other members of the quinine alkaloid family also form light-polarizing polyiodides by reaction with iodine and HI, such as cinchonidine bisulfate.
  • the elemental iodine combines with the alkaloid acid salt in the form of the polyiodide anion, which has been variously described as I 3 - by Godina et al and as I 5 - by Teitelbaum et al, JACS, 100 (1978) pages 3215-3217.
  • Godina et al show that the polyiodide anion is formed by reaction between iodine and HI, e.g.
  • light-polarizing polyiodides comprise the polyiodide anion and the acid salt of quinine and the like as the cation.
  • polyiodides can also be formed without any apparent cation being present, such as the starch-iodine complex and the stretched or oriented polyvinyl alcohol-iodine complex.
  • Teitelbaum et al report that the starch-iodine complex contains adsorbed iodine in the form of chains of iodine within the amylase component of starch, the chains being made up of I 5 - polyiodide anions as the dominant species.
  • herapathite, starch-iodine and oriented PVA-iodine complex are "adsorbing polyiodides” in which molecular iodine is adsorbed in layers on the polyiodide chains.
  • the light-polarizing material of the present invention is a complex obtained by reacting (i) elemental iodine, (ii) a hydrohalide acid and/or an ammonium or alkali metal or alkaline earth metal halide and (iii) a compound of formula I or II below.
  • This complex contains adsorbed molecular iodine.
  • the complex also contains the polyiodide anion, I x - , where x is 3 or 5, since Godina et al and Teitelbaum et al both report that the polyiodide anion is formed by reaction between (i) elemental iodine and (ii) an iodide.
  • Godina et al report that crystals containing adsorbed molecular iodine and the polyiodide anion are light-polarizing.
  • light polarizing materials are prepared by reacting a compound I or II with iodine and an iodide, bromide or chloride. In such cases, the respectively anions would be
  • the light-polarizing material of the present invention is defined in product-by-process format.
  • the lower alkyl may be straight or branched chain alkyl, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl and the like.
  • the lower alkyl will have from 1 to about 6 carbon atoms.
  • the solubility of compound I or II in organic solvents increases and the solubility in water decreases as the number of carbon atoms of the lower alkyl substituents increases.
  • the desired balance of organic solvent/water solubility may be obtained by appropriate selection of the lower alkyl groups.
  • Compounds I and II are known per se or may be isomers, homologues or analogs of known compounds and may be prepared analogously to such known compounds.
  • Useful compounds of formulas I and II include:
  • the light-polarizing materials of this invention are formed by reacting a compound of formula I or II with elemental iodine and a hydrohalide acid and/or an ammonium, alkali metal or alkaline earth metal halide, in a suitable solvent, such as alcohol or etheralcohol.
  • a suitable solvent such as alcohol or etheralcohol.
  • the halide is usually an iodide, but can also be a bromide or chloride.
  • the reaction to form the polyhalide takes place in the presence of a protective colloid, such as nitrocellulose or a copolymer as disclosed in U.S. Pat. No. 4,164,365, issued Aug. 14, 1979.
  • the polyhalide particles are suspended in a liquid suspending medium.
  • the liquid suspending medium may be virtually any electrically resistive liquid so long as it suspends the particles and dissolves the polymeric stabilizer.
  • the liquid suspending medium has a relatively high electrical resistivity and low vapor pressure, and does not degrade or attack the particles or other components of the suspension. See e.g. U.S. Pat. Nos. 4,270,841 and 4,407,565 to Saxe.
  • the polyhalide particles are dispersed or distributed throughout a sheet formed of suitable film-forming material, such as cellulose acetate or polyvinylalcohol or the like. See e.g. U.S. Pat. Nos. 2,178,996 and 2,041,138.
  • Examples 4-6 are repeated but with an effective amount of CaBr 2 substituted for CaI 2 .
  • Light-polarizing crystals having a somewhat different bluish color are formed.
  • Examples 4-6 are repeated but with an effective amount of CaCl 2 substituted for CaI 2 .
  • Light-polarizing crystals having a somewhat different bluish color are formed.
  • Some of the compounds I and II used in the present invention are known to form metal salts and/or to be metal-chelating compounds. Accordingly, one possible explanation for the formation of the light-polarizing materials of this invention is that when the compounds I or II are reacted with iodine and a halide, the halide and iodine enter into the reaction in an ionic form.
  • the halide is calcium iodide
  • CaI 2 , iodine may enter the reaction as Ca +2 (I x ) 2 - , with the positively charged calcium ion being chelated by compounds I and II and the (I x ) - anion being bonded to the positive calcium ion, thereby forming a polyiodide crystal. While this explanation seems reasonable, it is not intended that this application be bound by this theory.
  • Liquid suspensions of the polyhalide particles of this invention can be easily prepared by utilizing a procedure somewhat similar to that for preparing liquid suspensions of dihydrocinchonidine sulfate polyiodide described in Example 2 of U.S. Pat. No. 4,131,334 and in Example 1 of U.S. Pat. No. 4,407,565, but with compounds I and II of the present invention substituted for dihydrocinchonidine sulfate and the quantities of the reactants adjusted as, for example, given in the aforesaid examples and in U.S. patent application Ser. No. 309,693, now U.S. Pat. No. 4,877,313, issued Oct. 31, 1989.
  • the liquid suspensions of the present invention will be stable at temperatures of 85° C. or more and will withstand prolonged exposure to ultraviolet radiation.
  • Liquid suspensions of the type described above can be used in light valves which utilize an AC electric field to orient the particles in said suspensions to change and/or control the transmission of light through the suspension.
  • Such light valves can be used, for example, as variable transmission windows, filters, mirrors, and eyeglasses, and as electronic alphanumeric and graphic image displays.
  • a set suspension of the particles of the present invention would comprise, for example, a light-polarizing sheet or film in which said particles would be incorporated along with other materials.
  • U.S. Pat. No. 2,178,996 discloses a process for forming certain light-polarizing particles, mixing said particles into a dispersion medium which may include cellulose acetate, and subjecting the dispersion of particles to flow or extrusion or stretch, or rolling, so that the needle axis of the dispersed polarizing crystals may be oriented to substantial parallelism and a thin, sheet-like polarizing body produced.
  • U.S. Pat. No. 2,041,138 discloses that polarizing bodies may preferably be made in the form of a relatively thin sheet or film comprising the suspending medium and the minute particles dispersed therein.
  • the polarizing body may itself be permanently or detachably fixed to a suitable support, preferably transparent, as for example, to a plate of glass or to a sheet of celluloid.
  • a suitable support preferably transparent, as for example, to a plate of glass or to a sheet of celluloid.
  • Such a support may be desirable with conditions where it is found that the polarizing body itself may require some form of protection. It also discloses the use of asymmetric particles, the flowing of the medium that includes said particles past an edge, and retaining said particles in an oriented position by setting or hardening said medium.
  • U.S. Pat. No. 2,168,220 discloses information relating to polarizing material sold under the trade name "Polaroid”. Use of plasticizers, adhesives and various types of laminations and methods for forming said laminations are disclosed.
  • the polarizers made from set suspensions of the particles and other materials of the present invention will be stable to high levels of heat and ultraviolet radiation and will tolerate water excellently. Accordingly, the present invention makes possible a substantial improvement in the quality of light-polarizing bodies and products incorporating such materials.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Nonlinear Science (AREA)
  • Polarising Elements (AREA)
  • Liquid Crystal Substances (AREA)
  • Hybrid Cells (AREA)
  • Liquid Crystal (AREA)
  • Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)
  • Orthopedics, Nursing, And Contraception (AREA)
US07/428,103 1985-06-10 1989-10-27 Light polarizing materials and suspensions thereof Expired - Lifetime US5002701A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
CA000602176A CA1336858C (en) 1986-09-30 1989-06-08 Light polarizing materials and suspensions thereof
US07/428,103 US5002701A (en) 1989-02-10 1989-10-27 Light polarizing materials and suspensions thereof
CA002027349A CA2027349C (en) 1989-10-27 1990-10-15 Light polarizing materials and suspensions thereof
DE69008999T DE69008999T2 (de) 1989-10-27 1990-10-17 Leichtpolarisierende Materialien und deren Suspensionen.
EP90402918A EP0425344B1 (de) 1989-10-27 1990-10-17 Leichtpolarisierende Materialien und deren Suspensionen
KR1019900016868A KR0168652B1 (ko) 1989-10-27 1990-10-22 편광물질과 그 현탁액
JP2288254A JP2871837B2 (ja) 1989-10-27 1990-10-25 偏光材料及び該偏光材料を含む光弁用液状懸濁液
US07/608,534 US5130057A (en) 1985-06-10 1990-11-02 Light polarizing materials and suspensions thereof

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US07/309,693 US4877313A (en) 1986-09-30 1989-02-10 Light-polarizing materials and suspensions thereof
CA000602176A CA1336858C (en) 1986-09-30 1989-06-08 Light polarizing materials and suspensions thereof
US07/428,103 US5002701A (en) 1989-02-10 1989-10-27 Light polarizing materials and suspensions thereof

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US07/309,693 Continuation-In-Part US4877313A (en) 1985-06-10 1989-02-10 Light-polarizing materials and suspensions thereof

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US07/608,534 Division US5130057A (en) 1985-06-10 1990-11-02 Light polarizing materials and suspensions thereof

Publications (1)

Publication Number Publication Date
US5002701A true US5002701A (en) 1991-03-26

Family

ID=23697569

Family Applications (1)

Application Number Title Priority Date Filing Date
US07/428,103 Expired - Lifetime US5002701A (en) 1985-06-10 1989-10-27 Light polarizing materials and suspensions thereof

Country Status (6)

Country Link
US (1) US5002701A (de)
EP (1) EP0425344B1 (de)
JP (1) JP2871837B2 (de)
KR (1) KR0168652B1 (de)
CA (1) CA2027349C (de)
DE (1) DE69008999T2 (de)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5093041A (en) * 1990-07-30 1992-03-03 Research Frontiers Incorporated Light-polarizing material based on ethylenediamine polyacetic acid derivatives
EP0635734A3 (de) * 1993-07-21 1996-04-17 Research Frontiers Inc Verfahren zur Herstellung von leichtpolarisierenden Partikeln.
US5650872A (en) * 1994-12-08 1997-07-22 Research Frontiers Incorporated Light valve containing ultrafine particles
US5739296A (en) * 1993-05-21 1998-04-14 Russian Technology Group Method and materials for thermostable and lightfast dichroic light polarizers
WO1999043983A1 (en) * 1998-02-26 1999-09-02 Research Frontiers Incorporated Light polarizing materials, liquid suspensions and films thereof, and light valves incorporating same
WO2000003178A1 (en) * 1998-07-09 2000-01-20 Research Frontiers Incorporated Polyhalide particles and light valves comprising same
US6334967B1 (en) 1998-07-09 2002-01-01 Rsearch Frontiers Incorporated Light-polarizing particles of improved particle size distribution
US6429961B1 (en) 2000-10-03 2002-08-06 Research Frontiers Incorporated Methods for retrofitting windows with switchable and non-switchable window enhancements
US6515787B1 (en) 2000-03-07 2003-02-04 Eclipse Energy Systems, Inc. Electrochromic layer
US6517746B1 (en) 1998-07-09 2003-02-11 Research Frontiers Incorporated Polyhalide particles and light valves comprising same
US6522446B2 (en) 2001-04-25 2003-02-18 Research Frontiers Incorporated Anisometrically shaped metal particles, liquid suspensions and films thereof and light valves comprising same
US6529312B1 (en) 1999-06-07 2003-03-04 Research Frontiers Incorporated Anisometrically shaped carbon and/or graphite particles, liquid suspensions and films thereof and light valves comprising same
US20030107797A1 (en) * 1999-06-07 2003-06-12 Research Frontiers Incorporated Anisometrically shaped carbon and/or graphite particles, liquid suspensions and films thereof and light valves comprising same
US6606185B2 (en) 2001-06-12 2003-08-12 Research Frontiers Incorporated SPD films and light valves comprising liquid suspensions of heat-reflective particles of mixed metal oxides and methods of making such particles
KR100399717B1 (ko) * 1998-07-09 2003-09-29 리서치 프론티어스 인코퍼레이티드 폴리할라이드 편광재 및 이것의 제조 방법
US20040160660A1 (en) * 2003-02-13 2004-08-19 Research Frontiers Incorporated Method and device for controlling voltage provided to a suspended particle device
US20060158805A1 (en) * 2005-01-18 2006-07-20 Research Frontiers Inc. Methods and circuits for distributing power to SPD loads
US7145709B1 (en) 2002-10-25 2006-12-05 Eclipse Energy Systems, Inc. Apparatus and methods for modulating refractive index
US20090241424A1 (en) * 2008-06-06 2009-10-01 Msa Aircraft Products Ltd. Modular Window For An Aircraft Including An SPD Lens And An Opaque Shade

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR960014118B1 (ko) * 1992-01-10 1996-10-14 한국유리공업 주식회사 광편광현탁액이 고분자수지내에 분산된 투과도 가변창용 필름 및 그 제조방법
ATE175197T1 (de) * 1992-04-07 1999-01-15 Research Frontiers Inc Licht-polarisierendes material basierend auf chinaldinsäurederivaten
JP5849393B2 (ja) 2008-05-15 2016-01-27 日立化成株式会社 光調整粒子の製造方法及び該製造方法で得られた光調整粒子を用いた調光フィルム
JP5139935B2 (ja) * 2008-09-22 2013-02-06 日東電工株式会社 ヨウ素系偏光フィルム及びその製造方法

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4877313A (en) * 1986-09-30 1989-10-31 Research Frontiers Incorporated Light-polarizing materials and suspensions thereof

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4270841A (en) * 1978-10-31 1981-06-02 Research Frontiers Incorporated Light valve containing suspension of perhalide of alkaloid acid salt
JP2798426B2 (ja) 1989-07-07 1998-09-17 リサーチ フロンティアーズ インコーポレーテッド 偏光材料及びその懸濁物

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4877313A (en) * 1986-09-30 1989-10-31 Research Frontiers Incorporated Light-polarizing materials and suspensions thereof

Cited By (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5093041A (en) * 1990-07-30 1992-03-03 Research Frontiers Incorporated Light-polarizing material based on ethylenediamine polyacetic acid derivatives
US6174394B1 (en) 1993-05-21 2001-01-16 Optiva, Inc. Method for thermostable and lightfast dichroic light polarizers
US5739296A (en) * 1993-05-21 1998-04-14 Russian Technology Group Method and materials for thermostable and lightfast dichroic light polarizers
EP0635734A3 (de) * 1993-07-21 1996-04-17 Research Frontiers Inc Verfahren zur Herstellung von leichtpolarisierenden Partikeln.
US5516463A (en) * 1993-07-21 1996-05-14 Research Frontiers Incorporated Method of making light-polarizing particles
AU682367B2 (en) * 1993-07-21 1997-10-02 Research Frontiers Incorporated Method of making light-polarizing particles
US5650872A (en) * 1994-12-08 1997-07-22 Research Frontiers Incorporated Light valve containing ultrafine particles
US6156239A (en) * 1998-02-26 2000-12-05 Research Frontiers Incorporated Light polarizing materials, liquid suspensions and films thereof, and light valves incorporating same
WO1999043983A1 (en) * 1998-02-26 1999-09-02 Research Frontiers Incorporated Light polarizing materials, liquid suspensions and films thereof, and light valves incorporating same
WO2000003178A1 (en) * 1998-07-09 2000-01-20 Research Frontiers Incorporated Polyhalide particles and light valves comprising same
US6334967B1 (en) 1998-07-09 2002-01-01 Rsearch Frontiers Incorporated Light-polarizing particles of improved particle size distribution
KR100399717B1 (ko) * 1998-07-09 2003-09-29 리서치 프론티어스 인코퍼레이티드 폴리할라이드 편광재 및 이것의 제조 방법
US6517746B1 (en) 1998-07-09 2003-02-11 Research Frontiers Incorporated Polyhalide particles and light valves comprising same
US20030107797A1 (en) * 1999-06-07 2003-06-12 Research Frontiers Incorporated Anisometrically shaped carbon and/or graphite particles, liquid suspensions and films thereof and light valves comprising same
US6529312B1 (en) 1999-06-07 2003-03-04 Research Frontiers Incorporated Anisometrically shaped carbon and/or graphite particles, liquid suspensions and films thereof and light valves comprising same
US6987602B2 (en) 1999-06-07 2006-01-17 Research Frontiers Incorporated Anisometrically shaped carbon and/or graphite particles, liquid suspensions and films thereof and light valves comprising same
US6822778B2 (en) 2000-03-07 2004-11-23 Eclipse Energy Systems, Inc. Electrochromic layer
US6515787B1 (en) 2000-03-07 2003-02-04 Eclipse Energy Systems, Inc. Electrochromic layer
US20030137712A1 (en) * 2000-03-07 2003-07-24 Eclipse Energy Systems, Inc. Electrochromic layer
US6429961B1 (en) 2000-10-03 2002-08-06 Research Frontiers Incorporated Methods for retrofitting windows with switchable and non-switchable window enhancements
US6522446B2 (en) 2001-04-25 2003-02-18 Research Frontiers Incorporated Anisometrically shaped metal particles, liquid suspensions and films thereof and light valves comprising same
US6606185B2 (en) 2001-06-12 2003-08-12 Research Frontiers Incorporated SPD films and light valves comprising liquid suspensions of heat-reflective particles of mixed metal oxides and methods of making such particles
US7145709B1 (en) 2002-10-25 2006-12-05 Eclipse Energy Systems, Inc. Apparatus and methods for modulating refractive index
US6804040B2 (en) 2003-02-13 2004-10-12 Research Frontiers Incorporated Method and device for controlling voltage provided to a suspended particle device
US6897997B2 (en) 2003-02-13 2005-05-24 Research Frontiers Incorporated Method and device for controlling voltage provided to a suspended particle device
US20040165251A1 (en) * 2003-02-13 2004-08-26 Research Frontiers Incorporated Method and device for controlling voltage provided to a suspended particle device
US20040160660A1 (en) * 2003-02-13 2004-08-19 Research Frontiers Incorporated Method and device for controlling voltage provided to a suspended particle device
US20060158805A1 (en) * 2005-01-18 2006-07-20 Research Frontiers Inc. Methods and circuits for distributing power to SPD loads
US7417785B2 (en) 2005-01-18 2008-08-26 Research Frontiers Incorporated Methods and circuits for distributing power to SPD loads
US20080204856A1 (en) * 2005-01-18 2008-08-28 Research Frontiers Corporation Methods and circuits for distributing power to spd loads
US8174753B2 (en) 2005-01-18 2012-05-08 Research Frontiers Inc. Methods and circuits for distributing power to SPD loads
US20090241424A1 (en) * 2008-06-06 2009-10-01 Msa Aircraft Products Ltd. Modular Window For An Aircraft Including An SPD Lens And An Opaque Shade

Also Published As

Publication number Publication date
EP0425344A2 (de) 1991-05-02
JP2871837B2 (ja) 1999-03-17
DE69008999T2 (de) 1994-12-22
JPH03167290A (ja) 1991-07-19
CA2027349A1 (en) 1991-04-28
CA2027349C (en) 2001-02-06
KR910008431A (ko) 1991-05-31
KR0168652B1 (ko) 1999-04-15
EP0425344A3 (de) 1991-07-10
EP0425344B1 (de) 1994-05-18
DE69008999D1 (de) 1994-06-23

Similar Documents

Publication Publication Date Title
US5002701A (en) Light polarizing materials and suspensions thereof
US4877313A (en) Light-polarizing materials and suspensions thereof
CA2065500C (en) Light-polarizing material based on quinaldic acid derivatives
US5130057A (en) Light polarizing materials and suspensions thereof
US3774988A (en) Variable light-filtering device
US4422963A (en) Light valve polarizing materials and suspensions thereof
US4270841A (en) Light valve containing suspension of perhalide of alkaloid acid salt
EP0564676B1 (de) Licht-polarisierendes Material basierend auf Chinaldinsäurederivaten
EP0403711B1 (de) Lichtpolarisierende Teilchen und Suspensionen aus derartigen Teilchen
KR100365576B1 (ko) 편광 재료, 이의 액체 현탁액 및 필름과, 이들을 함유하는 광 밸브
US5071234A (en) Polarization film
AU737670B2 (en) Light-polarizing particles of improved particle size distribution
JP2798426B2 (ja) 偏光材料及びその懸濁物
CA1336858C (en) Light polarizing materials and suspensions thereof
JP3187874B2 (ja) エチレンジアミンポリ酢酸をベースとする光−偏光性物質
CA2049869C (en) Light-polarizing material based on ethelenediamine polyacetic acid derivatives
US4131334A (en) Light polarizing materials, suspensions thereof, and process for manufacturing such suspensions
KR100255249B1 (ko) 에틸렌디아민 폴리아세트산 유도체를 기초로한 편광물질
DE69117507T2 (de) Lichtpolarisierendes Material auf Basis von Äthylendiaminpolyessigsäurederivaten
KR0153272B1 (ko) 광편광체 및 이의 현탁액
US6517746B1 (en) Polyhalide particles and light valves comprising same
US6334967B1 (en) Light-polarizing particles of improved particle size distribution
CA2336347C (en) Polyhalide particles and light valves comprising same
JPH0565842B2 (de)
JPH0458222A (ja) 調光機能を有する光学素子用膜及びそれを用いた光学素子

Legal Events

Date Code Title Description
AS Assignment

Owner name: RESEARCH FRONTIERS INCORPORATED, NEW YORK

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:SAXE, ROBERT L.;REEL/FRAME:005168/0322

Effective date: 19891026

AS Assignment

Owner name: RESEARCH FRONTIERS INCORPORATED, A CORP. OF DE

Free format text: MERGER;ASSIGNOR:RESEARCH FRONTIERS INCORPORATED, A NY CORP.;REEL/FRAME:005401/0234

Effective date: 19891215

STCF Information on status: patent grant

Free format text: PATENTED CASE

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

FEPP Fee payment procedure

Free format text: PAYER NUMBER DE-ASSIGNED (ORIGINAL EVENT CODE: RMPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12